1. Technical Field
The present invention relates to a seal member configured to communicate flow channels in a liquid-tight manner, a liquid discharge head having the seal member, and a liquid discharge apparatus.
2. Related Art
Examples of a liquid discharge head include an ink jet recording head used for an image recording apparatus such as an ink jet recording apparatus. In recent years, however, the liquid discharge head is applied to various manufacturing apparatuses by making full use of such a feature that liquid of a very small amount can be landed accurately onto a predetermined position.
For example, the liquid discharge head is applied to display manufacturing apparatuses configured to manufacture color filters such as liquid-crystal displays, electrode forming apparatuses configured to form electrodes for organic EL (Electro Luminescence) displays and FEDs (Face Emitting Displays), Chip manufacturing apparatuses configured to manufacture biochips. Recording heads for the image recording apparatuses are configured to discharge liquid-state ink, and color material discharging heads for the display manufacturing apparatuses are configured to discharge solutions of color materials in R (red), G (green), and B (blue). Electrode material discharge heads for the electrode forming apparatuses discharge liquid-state electrode material, and bioorganic substance discharge heads for chip manufacturing apparatuses discharge bioorganic substance solution.
Examples of such a liquid discharge head include a configuration in which a plurality of components are stacked one on top of another. The liquid discharge head in this configuration includes a seal member configured to make ink flow channels formed on the components communicate with each other (for example, see JP-A-2012-240209). The seal member achieves sealing properties (that is, liquid-tight properties) between the flow channels by coming into tight contact with an opening rims of the flow channels. Therefore, in general, the seal member is formed of an elastic material such as elastomer. The seal member configured as described above is used not only in the liquid discharge head but preferably also for sealing members having the liquid flow channels with each other.
The seal member formed of a material containing a plasticizer for providing elasticity like elastomer, and butyl rubber, and the like gradually loses the plasticizer in a course of being used depending on the type of liquid (for example, solvent ink) passing therethrough, and, meanwhile, the plasticizer is replaced by ink or the like. Consequently, the ink or the like penetrated in the seal member volatilizes, for example, when exposed to a high-temperature and dry environment, and dimensions of the seal member is contracted as a whole, which could lead to misalignment of communicating holes of the seal member with respect to the flow channels to be sealed. As a result, flow channels may be clogged, or liquid may leak due to an impairment of sealing properties.